I beleive G1 doesn't support AF for 50mm f2 lens. I use this lens with my E-PL2 via MMF-2 adapter and it performs wonderfully. AF is certainly fast enough in most situations so no need to MF. It's a great portrait lens and it's as sharp as Panny 20mm!

I used this lens on E-PL1 and it focuses rather slow but still usable. it is VERY sharp a lens as all the reviews are saying, is the lens of choice to to test Oly cameras on dpreview. Works great for macro and portraits.